The present invention relates to the routing of electronic messages over a telecommunications system containing both satellite and ground-based elements.
In a satellite communications system, an electronic message is sent from a Subscriber Communicator (xe2x80x9cSCxe2x80x9d), e.g., a ground-based communications transceiver, to the satellite covering the geographic region in which the SC is operating. Upon receiving the electronic message, the satellite transmits the electronic message to an appropriate Gateway Earth Station (xe2x80x9cGESxe2x80x9d). The GES receives the message and sends it to the system operator""s Gateway Control Center (xe2x80x9cGCCxe2x80x9d) for delivery to the recipient.
A SC-originated message is routed from the GCC to the recipient based on the recipient""s address, similar to how letters are delivered by the post office. For example, the message might travel along a dedicated link from the GCC to a Value Added Reseller""s (xe2x80x9cVAR""sxe2x80x9d) Message Transfer Agent (MTA), where services such as automated. language translation can be applied to the message. Then, the message is routed to the recipient across a public network. Alternatively, the message might travel along a public network from the GCC directly to the recipient. The public network link from the GCC to the recipient could be any one of the available public services, e.g., the Internet or a Plain Old Telephone System dial-up line.
A message sent to a SC generally may travel over any one of multiple routes from the originator to the GCC, including a public network route to a VAR""s MTA or a public network route directly to the GCC. The route through the VAR""s MTA to the GCC may include a dedicated link between the MTA and the GCC. When a message is received at the GCC, it is sent to the GES that is connected to the GCC. The GES transmits the message to the appropriate satellite, which transmits the message to the SC.
Service providers for the SCs typically are authorized to provide such service only for a geographically distinct area, e.g., a single country. In prior art systems, the service provider is required to have a GCC to control electronic communications originating or terminating within the service provider""s coverage area. This is true even though a GCC is capable of handling the electronic communications for a large region, e.g., Western Europe, encompassing more than one service provider""s authorized territory.
Using a single, regional GCC to control electronic message traffic for a large, multi-country region, i.e., xe2x80x9cregionalization,xe2x80x9d is not presently feasible in some cases using prior art systems due to commercial and political concerns. The primary commercial concern is that regionalization reduces a service provider""s control over messages sent to and from SCs provisioned by the service provider. Therefore, the service provider has limited ability to be compensated appropriately for messages originating from or terminating in the service provider""s territory and involving the service provider""s customers. Additionally, the service provider has limited ability to control the access granted to SCs (i.e., customers) provisioned by the service provider and to provide additional services such as language translation and billing services. Further, the legal requirements of many countries require a local (i.e. in-country) entity to control all electronic communications originating or terminating within the country.
The present invention overcomes the commercial and political roadblocks presently frustrating the use of regional GCCs by providing service providers with message routing capability for all messages to or from SCs provisioned by the service provider without requiring any GCC to be dedicated to only a single service provider.
The present invention allows a service provider to control and manage messages to and from the SCs provisioned by the service provider without having a dedicated GCC. The service provider can then provide, for example, the following services: customer billing; customer services tailored to the needs of a specific customer; statistical compilation and reporting of message traffic; and control over messages for regulatory purposes. The present invention provides these benefits at a significantly lower cost than the cost of a dedicated GCC. Additionally, the present invention provides greater routing control than MTA software insofar as the present invention provides dual method routing control, compared to the single method routing control provided by MTA software.
A MTA is a computer system that routes electronic mail according to the destination address. This routing determination is invisible to the sender and recipient. MTA software routes electronic messages according to the standards and specifications developed by and for the International Telecommunications Union, in particular the X.400 standards. Various companies have developed MTA software to implement the X.400 standards.
Messages to or from a SC are routed through a Message Distribution Center (xe2x80x9cMDCxe2x80x9d) of the present invention operated by the service provider that provisioned the SC. The MDC routes messages based on either the originator""s or the recipient""s X.400 address depending on whether the message originates at a SC or terminates at a SC, respectively. Where a message is addressed in Simple Mail Transfer Protocol (SMTP) format, e.g., localpart@domain.com, the recipient""s address is converted to X.400 format at the regional GCC. This routing method is similar to routing a letter through a particular post office based on the letter""s return address.
All of the hardware and software components for the MDC, with the exception of the MDC Transfer Module (xe2x80x9cMTMxe2x80x9d), described below, are available as commercial, off-the-shelf products. The MDC hardware consists of a group of fault tolerant servers, routers, hubs, and uninterruptable power supplies. The MDC software includes commercial, off-the-shelf MTA and firewall software packages and a MTA equipped with Message Store functionality and a SMTP/MIME gateway (defined below).
The MTM is a software module that encapsulates and de-encapsulates a message that originated with a SC provisioned by a service provider operating a MDC. One software module is placed in the regional GCC and another is placed in the service provider""s MDC. When a message that was sent from a SC provisioned by a service provider operating a MDC arrives at a regional GCC, the MTM software module in the GCC converts the recipient address so that the message will be routed to the service provider""s MDC. When the message arrives at the MDC, the MTM software module on the MDC reverses the address conversion made at the GCC so that the message can be routed to the intended recipient via public networks.
The MDC is connected to the regional GCC via a dedicated frame relay link and a permanent virtual circuit. A dedicated frame relay link is a data link using the public telephone and telegraph systems to deliver switched, packetized data from the MDC to the GCC and vice-versa. A permanent virtual circuit is a logical connection through a frame relay network. A permanent virtual circuit is a logical connection through a frame relay network.
A second, back-up, connection from the MDC to the regional GCC is an Integrated Services Digital Network (xe2x80x9cISDNxe2x80x9d) Basic Rate Interference connection from the public switched telephone network. A tertiary method of connection, in case the primary and secondary methods fail, is an analog dial up connection using the public switched telephone network.